Toshiba Qosmio X300 Series, Maintenance Manual

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Qosmio X300 Maintenance Manual 1-14
1.4 Power Supply
The power supply unit provides constant voltage 19V for the system board and performs the
following functions:
1. Power input monitor
y
Checks whether the AC adapter (DC power supply) is connected to the computer.
y
Checks whether the battery pack is connected to the computer.
y
Monitors the DC power supply input voltage (AC Adapter output voltage).
2. Power supply's internal control
y
Turns on and off the battery pack charging power supply.
y
Issues a charging current instruction to the PWM control IC of the battery pack charging
power supply.
y
Controls the supply of DC power supply input (AC Adapter output) to the power supply
unit.
y
Controls the supply of power to the system block (load/logic circuit side).
y
Controls forced shutdown if the power supply malfunctions.
3. Logic circuit control
y
Instructs the gate array to enable/disable tuning the power on.
y
Controls power-on/off operation.
4. Status display
y
Shows DC-IN (Red Color)
y
Shows Power (Red/Amber)
y
Shows Main Battery charging (Red/Amber Color).
5. External interface
y
Performs communication through the I2C bus (via the internal EC/KBC).
y
Transfers the power supply operation mode.